Conventionally, JP2003-221946A discloses a door handle apparatus. This type of door handle apparatus is provided with a door handle and a sensor electrode. The door handle includes both an inner space defined therein and a first wall portion having both an operation surface at an outer side thereof and a first inner surface at an inner side thereof, a first inner surface which serves as a part of a surface defining the inner space in the door handle. The sensor electrode is allocated within the interior space in such a manner so as to face the first inner surface of the first wall portion, and generates electrostatic capacitance between the sensor electrode and a dielectric approaching the operation surface of the door handle. A circuit portion is electrically connected to the sensor electrode. A human approach-detecting sensor is thus configured as described above. This circuit portion can detect variations in electrostatic capacitance generated at a time that a hand of a user is approaching the operation surface of the door handle and at a time that the hand is going way therefrom, thereby recognizing the fact that the hand is approaching the door handle.
As described in JP2003-221946A, when the human approach-detecting sensor having the sensor electrode and the circuit portion detects the fact that a human hand is approaching a door handle, in order to detect the approach of a human hand to the door handle, consideration should be most highly given to variations in electrostatic capacitance detected by the circuit portion. However, variations in electrostatic capacitance heavily depend on a distance between a sensor electrode incorporated in such a sensor and a hand of a user. In the event that, due to flexure of the first wall portion of the door handle, or due to a degree of precision of attaching the sensor electrode to the first wall portion, a distance of the sensor electrode relative to the operation surface of the first wall portion fluctuates, a distance, which is defined between the sensor electrode and a hand of a user already approaching the operation surface may alter. Therefore, notwithstanding a user's hand has already approached the door handle, there is a danger of the human approach-detecting sensor of failing to detect a user's hand that has approached the door handle, thereby deteriorating a detecting performance of the human approach-detecting sensor.
The present invention has been made in view of the above circumstances, and provides a vehicle door handle apparatus, which is simply structured and can stabilize a performance of a human approach-detecting sensor in detecting a dielectric.